Solar Glossary

Solar Battery Storage

Solar battery storage is a rechargeable battery system installed alongside solar panels to store surplus daytime electricity for use in the evening or during low-generation periods.

Solar Battery Storage explained

Solar battery storage is one of the most popular additions to a solar system. A battery stores the surplus electricity your solar panels generate during the day — power that would otherwise be exported cheaply to the grid — and releases it when the sun isn't shining, typically in the evenings.

How it changes your self-consumption: a typical UK household without a battery self-consumes 30–40% of their solar generation. Add a 10 kWh battery and that rises to 70–85%, dramatically reducing your grid import bills.

Popular residential battery systems in the UK (2024–2026):

  • Tesla Powerwall 3: 13.5 kWh, integrated solar inverter, ~£8,000–£11,000 installed
  • GivEnergy 9.5 kWh: popular mid-range system, ~£4,500–£6,500 installed
  • BYD HVM / HVS: modular batteries from 5.1 to 22.1 kWh, competitive pricing
  • SolarEdge Home Battery: deeply integrated with SolarEdge inverter systems

Battery payback periods are longer than panels alone (typically 8–14 years), but are improving as battery costs fall. The business case is strongest for households with time-of-use tariffs, EVs, or heat pumps that create significant evening demand. Batteries also provide backup power during grid outages on models with backup capability.

How this affects your solar decision

Adding battery storage is one of the biggest decisions when going solar — it changes your self-consumption, savings, and overall system cost. Use the Solar Battery Calculator to find out if a battery makes financial sense for you.

Find out if solar battery storage is worth it for your homeSolar Battery Calculator

Related terms

Battery Capacity (kWh)Battery capacity in kWh measures the total amount of energy a solar battery can store and is the key specification for determining whether a battery can meet your evening electricity needs.Depth of Discharge (DoD)Depth of discharge is the percentage of a battery's total capacity that is actually used before recharging — higher DoD means more usable energy but can reduce battery lifespan if taken too deep.Lithium-Ion BatteryLithium-ion batteries are the dominant technology used in solar energy storage systems, offering high energy density, long cycle life, and relatively low maintenance compared to older lead-acid batteries.Hybrid InverterA hybrid inverter combines a solar inverter and a battery inverter in one unit, managing power flow between your solar panels, battery storage, home, and the grid.Self-ConsumptionSelf-consumption is the proportion of your solar-generated electricity that you use directly in your home, rather than exporting to the grid.
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